If the first number is 3, the second number is 5, the third number is 7, and the fourth number is 9, then what is the nth number? Use the algebraic expression

If the first number is 3, the second number is 5, the third number is 7, and the fourth number is 9, then what is the nth number? Use the algebraic expression

3=1×2﹢1
5=2×2+1
7=3×2+1
9=4×2﹢1
The nth number = 2n + 1

I'll give you a series of numbers. Observe the arrangement rules carefully. What are the most reasonable values to fill in the brackets? 18.33, 22.42, 38.67, (...), 138.19

The last one should be 138.190. The rule is that the difference of the first one in each group is the square of 2,4,6,8, while the second one is the square of 3,5,7,9

I give you a sequence of numbers, but one of them is missing. I ask you to observe the arrangement of the sequence carefully, and then choose the most suitable one from the four options
Reasonable one, to fill the vacancy, make it conform to the original sequence of arrangement
1.44,52,59,73,83,94,（ ）
a.107 b.101 c.105 d.113

Choose a,
44 52 59 73 83 94 B
Last item - first item 8 7 14 10 11 A
Original number sequence digit + ten digit 8 7 14 10 11 13
A=13 B=94+13=107